• Convergence Security Journal
• /
• v.2 no.2
• /
• pp.155-164
• /
• 2002

A design implemented the $\delta$SAcc234bit Mask Data Insertion algorithm that can let the Mask which commercialized Wave Steganography had improved the problem that a filter ring was able to easily become and raised Capacity and extend the width that Cover-data was alternative. Also, it applied 3-Tier file encryption algorithm with a proposal in order to improve a security level of Mask. 3-Tier file encryption algorithm is the algorithm that a specific pattern improved the problem that appeared in Ciphertext according to a file. A design implemented the StegoWaveK model carried out Wave Steganography, using $\delta$SAcc234bit Mask Data Insertion algorithm and the 3-Tier file encryption algorithm that proposed in this paper.

• Journal of the Korean Society of Costume
• /
• v.59 no.1
• /
• pp.47-59
• /
• 2009

This paper aimed at the development of face covers which is face protection articles for blocking UV rays and yellow sands, with a view to assist the further activation of outdoor life. The four-stage design process of field study, design, design evaluation, final selection of designs was set up for the effective product development. Field study included on-line and off-line market survey on the products for sale in market and observation on those wearing face covers. Depth interviews were done to know consumer understandings and satisfaction levels for current face covers. The results of market survey showed that most of the face covers currently in the market were mask types, which were produced for the blocking of dust and yellow sands rather than UV ray protection. The major clients of the mask were the women in their 30's-50's and the designs for these clients were very limited. Since the number of younger women and men enjoy the outdoor sports has increased, the face covers for these people should be developed. For this purpose, the direction of new face cover design had 2 points: diversification of design in terms of color, material, shape and giving seasonal differences. 12 designs were designed on the first design stage, but after both wearing test by 16 testees and UV ray blocking test to evaluate these designs, 6 face cover designs were finally selected.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.9
• /
• pp.3298-3321
• /
• 2021

A lot of data hiding schemes have been proposed to embed secret data in the plain cover images or compressed images of various formats, including JPEG, AMBTC, VQ, etc. In this paper, we propose a production process of mosaic images based on three regular images of coffee beans. A primary image is first mimicked by the process to produce a mosaic cover image. A two-layer steganography is applied to hide secret data in the mosaic image. Based on the low visual quality of the mosaic cover image, its PSNR value can be improved about 1.5 dB after embedding 3 bpp. This is achieved by leveraging the newly proposed polarized search mask and the concepts of strong embedding and weak embedding. Applying steganography to the mosaic cover images is a completely new idea and it is promising.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.10
• /
• pp.185-193
• /
• 2022

This study attempted to compare and analyze the commercially available multi-use patterns to develop mask patterns suitable for the face types of adult women. Through this, it was intended to provide necessary data to mask pattern development and products. As a results of comparing the dimensions and shapes of commercial multi-use mask patterns, there was a significant difference in dimensions even though it was a L-size mask manufactured for adults. As a result of the appearance evaluation of the virtual outfit, there were significant differences by design in the vertical of the center front line, the cover and space of the mask, the height of the nose, and the lower part of the mask. The side also showed significant differences in the covering of the side of the face, the space of the side, and the width and length of the string. As a result of the appearance evaluation, Mask 4 received the best evaluation. The shape of the mask pattern had a large dart in the lower part of the nose so that it can cover the three-dimensional shape of the face, but there was a difference in the degree and angle of the curve depending on the mask. Although the upper part of the mask, the lower part of the mask, and the cheek part are in close contact, the evaluation of the mask pattern, which has room in the nose and mouth, was high. It is thought that the mask pattern should be set according to the upper length, lower length, and nose height of the mask through analysis of the face shape and dimensions.

• The Journal of Bigdata
• /
• v.7 no.1
• /
• pp.63-73
• /
• 2022

COVID-19 has continued from 2020 to the present, and many social changes have occurred. Wearing a mask has become mandatory, and if you do not wear a mask, you cannot use public facilities or restaurants. For this reason, most public facility entrances are equipped with a mask recognition system to check whether a mask is worn. However, it is unclear whether people who cover their mouths with a scarf or who do not wear a mask properly can be identified. In this study, we proposed an embedded mask recognition system using YOLOv5. Unlike the existing mask recognition system, it was able to distinguish not only whether a mask was worn, but also whether a mask was worn in various exceptional situations, such as a person with a scarf or a person covering their mouth with their hands, and showed excellent performance when mounted on the Nvida Jetson Nano Board.

• Korean Journal of Remote Sensing
• /
• v.29 no.1
• /
• pp.105-114
• /
• 2013

Desertification of the East Asia area induced by human's indiscriminate activities and natural causes has gradually expanded and demanded scientific research for monitoring and predicting land cover condition. Therefore, this research classified land types which were compared to MODIS land cover and analyzed the extent of barren zone effecting Korea through yellow dust using S10-DAY MVC NDVI from SPOT between 1999 and 2011. This study used unsupervised classification after processing NDVI Correction and Water Mask for eliminating noise values included in the data for enhancement of classification accuracy. The results of analysis are that there are active variations near the borders of desert, especially the Mongolian steppe and the Gobi Desert in central Asia. In addition, the extent of entire desert has been decreased in the middle of the last decade, although desertification is in going on in East Asia.

• Korean Journal of Remote Sensing
• /
• v.39 no.4
• /
• pp.425-440
• /
• 2023

Monitoring water surface has become one of the most prominent areas of research in addressing environmental challenges.Accurate and automated detection of watersurface in remote sensing imagesis crucial for disaster prevention, urban planning, and water resource management, particularly for a country where water plays a vital role in human life. However, achieving precise detection poses challenges. Previous studies have explored different approaches,such as analyzing water indexes, like normalized difference water index (NDWI) derived from satellite imagery's visible or infrared bands and using k-means clustering analysis to identify land cover patterns and segment regions based on similar attributes. Nonetheless, challenges persist, notably distinguishing between waterspectralsignatures and cloud shadow or terrain shadow. In thisstudy, our objective is to enhance the precision of water surface detection by constructing a comprehensive water database (DB) using existing digital and land cover maps. This database serves as an initial assumption for automated water index analysis. We utilized 1:5,000 and 1:25,000 digital maps of Korea to extract water surface, specifically rivers, lakes, and reservoirs. Additionally, the 1:50,000 and 1:5,000 land cover maps of Korea aided in the extraction process. Our research demonstrates the effectiveness of utilizing a water DB product as our first approach for efficient water surface extraction from satellite images, complemented by our second and third approachesinvolving NDWI analysis and k-means analysis. The image segmentation and binary mask methods were employed for image analysis during the water extraction process. To evaluate the accuracy of our approach, we conducted two assessments using reference and ground truth data that we made during this research. Visual interpretation involved comparing our results with the global surface water (GSW) mask 60 m resolution, revealing significant improvements in quality and resolution. Additionally, accuracy assessment measures, including an overall accuracy of 90% and kappa values exceeding 0.8, further support the efficacy of our methodology. In conclusion, thisstudy'sresults demonstrate enhanced extraction quality and resolution. Through comprehensive assessment, our approach proves effective in achieving high accuracy in delineating watersurfaces from satellite images.

• Korean Journal of Remote Sensing
• /
• v.20 no.4
• /
• pp.235-244
• /
• 2004

This study focuses on the assessment for proposed algorithm to discriminate cloudy pixels from snowy pixels through use of visible, near infrared, and short wave infrared channel data in VEGETATION-1 sensor embarked on SPOT-4 satellite. Traditional threshold algorithms for cloud and snow masks did not show very good accuracy. Instead of these independent masking procedures, K-Means clustering scheme is employed for cloud/snow discrimination in this study. The pixels used in clustering were selected through an integration of two threshold algorithms, which group ensemble the snow and cloud pixels. This may give a opportunity to simplify the clustering procedure and to improve the accuracy as compared with full image clustering. This paper also compared the results with threshold methods of snow cover and clouds, and assesses discrimination capability in VEGETATION channels. The quality of the cloud and snow mask even more improved when present algorithm is implemented. The discrimination errors were considerably reduced by 19.4% and 9.7% for cloud mask and snow mask as compared with traditional methods, respectively.

• Proceedings of the KSRS Conference
• /
• 2005.10a
• /
• pp.26-29
• /
• 2005

In order to compute cloud coverage statistics over Asian region, an operational scheme for masking cloud-contaminated pixels in Advanced Very High Resolution Radiometer (AVHRR) daytime data was developed, evaluated and presented. Dynamic thresholding was used with channell, 2 and 3 to automatically create a cloud mask for a single image. Then the IO-day cloud coverage imagery was generated over the whole Asian region along with cloud-free composite imagery. Finally the monthly based statistics were computed based on the derived cloud coverage imagery in terms of land cover and country. As a result, it was found that 20-day is required to acquire the cloud free data over the whole Asia using NOAA AVHRR. The to-day cloud coverage and cloud-free composite imagery derived in this research is available via the web-site http://webpanda.iis.u-tokyo.ac.jp/CloudCover/.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.9
• /
• pp.157-167
• /
• 2022

This study attempted to investigate what kind of perception people in their 20s have about masks and to find out the characteristics of each type by categorizing the perception. The Q methodology was used for the study. The cognition types of masks were categorized into three. Type 1 was a 'always wear impact-important type' that always wears masks and thinks masks affect non-verbal communication and the wearer's image. Type 2 was a 'function-important negative recognition type' that wears masks to prevent germs and thinks that masks have a great negative impact. Type 3 was a 'concealment wear positive image type' that wears a mask to cover the face and thinks that a person looks young when wearing a mask. It is thought that the development of masks of various designs and functions reflecting the needs of consumers should be carried out. Also, it is thought that various products should be developed and sold so that consumers can choose according to important considerations such as design, fit, and function.